7. Do not
ignore shear failure mechanisms
•If the shear capacity of structural members is not
sufficient to permit the formation of flexural
plastic hinges, shear failure will precede the formation of plastic hinges at the end of the member.
•In R/C members, even if the shear capacity is
sufficient, but lateral reinforcement
is not spaced close enough at the plastic hinge zones, the concrete may crush in the absence of sufficient
confinement.
•If this happens, the plastic capacity is suddenly
dropped to what can be provided by the
longitudinal steel alone.
•Very few of the computer programs used routinely for
push-over analysis consider either of the
above two scenarios.
•As a consequence, designers should be aware of these
problems and deal with them manually,
if the computer program they are using cannot
address these issues automatically.
